ND91-4 3-1/2" Aluminum Cone Full-Range Driver 4 Ohm

Quick Overview

The low distortion and high excursion capabilities of the Dayton Audio ND91-4 3-1/2" full-range driver make it an ideal candidate for miniature point-source monitors, surround speakers, and line arrays.

Product Highlights

  • Low distortion, full-range 65 Hz to 17 kHz performance
  • Rubber-edged black anodized aluminum alloy cone
  • Large excursion capability — 4.6 mm Xmax, 25 mm peak
  • Self-shielded Neo-Balanced motor structure with copper alloy shorting ring
  • 1" 4-layer underhung voice coil with polyimide former
  • 30 watts RMS power handling
  • Great for line arrays and micro monitors

Product Manuals / Spec Sheets / Downloads

Dayton Audio ND91-4 Specification Sheet
Dayton Audio ND91-4 Klippel Test Results
Dayton Audio ND91-4 Data Files

Buying Options

Dayton Audios ND91 aluminum cone full-range drivers are the latest addition to the acclaimed ND Series high output/low distortion neodymium transducers. By increasing the original ND90s voice coil diameter from 3/4" to 1" and adding a copper alloy shorting ring, the ND91-4 features even lower distortion and delivers better bass impact and dynamic range—with peak Xmax up to 25 mm!

This high-BL version further exploits the low distortion characteristics of the Neo-Balanced motors optimized magnetic field, making the ND91 drivers an excellent choice for full-range point-source speaker enclosures, as well as extremely accurate, high resolution line arrays.


Sealed Volume 0.01 ft.³
Sealed F3 132 Hz
Vented Volume 0.03 ft.³
Vented F3 73 Hz
* Enclosure volume/F3s based on BassBox "optimum" calculations

Speaker Series ND Series
Model Number ND91-4
Color Black
Unit of Measure Each
UPC 844632090448
Warranty - Parts 5 Years
Warranty - Labor 5 Years
Product Shipping Weight (lbs.) 0.7
Speaker Type Full-Range
Nominal Diameter 3.50"
Power Handling (RMS) 30 watts
Power Handling (max) 60 watts
Continuous Program Power --
Impedance 4 ohms
Sensitivity 85.6 dB @ 2.83V/1m
Frequency Response 65 - 17,000 Hz
Voice Coil Diameter 25 mm
Magnet Weight --
DC Resistance (Re) 4.3 ohms
Voice Coil Inductance (Le) 0.83 mH @ 1 kHz
Resonant Frequency (Fs) 74 Hz
Mechanical Q (Qms) 4.24
Electromagnetic Q (Qes) 0.45
Total Q (Qts) 0.41
Diaphragm Mass Inc. Airload (Mms) 4.8g
Moving Mass Of Diaphragm (Mmd) --
Mechanical Compliance of Suspension (Cms) 0.96 mm/N
Surface Area Of Cone (Sd) 30.4 cm²
Volume of Displacement (Vd) 12.2 cm³
BL Product (BL) 4.59 Tm
Compliance Equivalent Volume (Vas) 1.4 liters
Maximum Linear Excursion (Xmax) 4.6mm
Drivers Mechanical Losses (Rms) --
Cone / Diaphragm Material Aluminum Cone
Entry / Exit Diameter --
Surround Material Rubber
Voice Coil Wire Material Aluminum
Voice Coil Former Kapton® / Polyimide
Basket/Frame Material Steel
Magnet Material Ferrite
Overall Outside Diameter 103.5 mm
Overall Depth 63.4 mm
Baffle Cutout Diameter 85 mm
# Mounting Holes 4
Mounting Hole Diameter --
Bolt Circle Diameter --
Product Weight --